Q: Identify the differences between bacteria, viruses, fungi and parasites

A: VIRUS - A virus is a small infectious agent that can replicate only inside the living cells of organisms. Most viruses are too small to be seen directly with a light microscope. [ Viruses infect all types of organisms, from animals and plants to bacteria and archaea.[1] Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants, and the discovery of the

tobacco mosaic virus by Martinus Beijerinck in 1898, about 5,000 viruses have been described in detail,[3] although there are millions of different types.[4] Viruses are found in almost every ecosystem on Earth and are the most abundant type of biological entity.The study of viruses is known as virology, a sub-speciality of microbiology. FUNGI A fungus (pronounced /'f??g?s/; pl. fungi[3] or funguses[4]) is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds (British English: moulds), as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose. These and other differences show that the fungi form a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (a monophyletic group). This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology, which is often regarded as a branch of botany, even though genetic studies have shown that fungi are more closely related to animals than to plants. PARASITE the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that went beyond one host (e.g. Taenia solium), which are now called macroparasites (typically protozoa and helminths). Parasites can now also refer to microparasites, which are typically smaller, such as viruses and bacteria and can be directly transmitted between hosts of one species. ]